Augmented reality devices are increasingly in use for various uses and activities, from military or sports uses such as aviation and navigation, to gaming applications and museum visits. Usually, augmented reality devices are used to enhance the orientation ability and receive various kinds of information without needing to cease the activity and without needing to gaze down to guidance books.
Controlling a user interface in an augmented-reality-enabled hardware device usually requires free hands for controlling the device by touch pads, hand gestures or other known manual control methods. Some other devices use, for example, voice activation.